ARM: dts: am57xx-beagle-x15/am57xx-idk: Fix pinctrl-names

The IO lines of MMC2 in am57xx-beagle-x15/am57xx-idk is connected to
3.3v. Use "ddr_3_3v" instead of "ddr_1_8v" to indicate DDR mode
works in 3.3v on these boards.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am571x-idk.dts

@@ -113,7 +113,7 @@ &mmc1 {
 };
 
 &mmc2 {
-	pinctrl-names = "default", "hs", "ddr_1_8v";
+	pinctrl-names = "default", "hs", "ddr_3_3v";
 	pinctrl-0 = <&mmc2_pins_default>;
 	pinctrl-1 = <&mmc2_pins_hs>;
 	pinctrl-2 = <&mmc2_pins_ddr_rev20 &mmc2_iodelay_ddr_conf>;

arch/arm/boot/dts/am572x-idk.dts

@@ -31,7 +31,7 @@ &mmc1 {
 };
 
 &mmc2 {
-	pinctrl-names = "default", "hs", "ddr_1_8v";
+	pinctrl-names = "default", "hs", "ddr_3_3v";
 	pinctrl-0 = <&mmc2_pins_default>;
 	pinctrl-1 = <&mmc2_pins_hs>;
 	pinctrl-2 = <&mmc2_pins_ddr_rev20>;

arch/arm/boot/dts/am574x-idk.dts

@@ -35,7 +35,7 @@ &mmc1 {
 };
 
 &mmc2 {
-	pinctrl-names = "default", "hs", "ddr_1_8v";
+	pinctrl-names = "default", "hs", "ddr_3_3v";
 	pinctrl-0 = <&mmc2_pins_default>;
 	pinctrl-1 = <&mmc2_pins_default>;
 	pinctrl-2 = <&mmc2_pins_default>;

arch/arm/boot/dts/am57xx-beagle-x15.dts

@@ -28,7 +28,7 @@ &mmc1 {
 };
 
 &mmc2 {
-	pinctrl-names = "default", "hs", "ddr_1_8v";
+	pinctrl-names = "default", "hs", "ddr_3_3v";
 	pinctrl-0 = <&mmc2_pins_default>;
 	pinctrl-1 = <&mmc2_pins_hs>;
 	pinctrl-2 = <&mmc2_pins_ddr_3_3v_rev11 &mmc2_iodelay_ddr_3_3v_rev11_conf>;